Because shape orientation matters, precise placement is essential
Just because something is available online does not mean it is regulated or medically endorsed
Many protocols are time-based (for example, evening use to match circadian goals) and cycle-based (used for a defined period, then paused)
Scientific References: Le Roith D, Bondy C, Yakar S, Liu JL, Butler A., Endocrine Reviews , 2001
Hydroquinone and other skin lighteners work for those with dark pigmentation under their eyes (although do seek a doctors opinion first because usually darkness under the eyes is actually very thin skin with blood vessels showing through it and lightening agents will not help, but could hurt thin skin) 5
10.1038/nature742 43 EzikeT